When using the xffm to delete some oddly named files, I lost about 90% of the contents of my home directory, dot-files included. The oddly named files began with "-(" or "-[", so they were awkward to delete from terminal because bash kept trying to interpret them as options for rm. I tried to use the GUI to get rid of this problem, and therefore fired up xffm and selected the two files and hit delete. It then deleted the vast majority of my home directory (I know that I didn't accidentally select other files because it hit the dot-files as well) without warning. The two target files are still there. Reproducible: Didn't try Steps to Reproduce: I haven't tried to reproduce, and am not feeling particularly inclined to. Running the 2.6.13 kernel on a Gentoo AMD-64 box. GTK+ 2.6.8. No log files or traces that I can see.
Did you send the files to the wastebasket? If so, then xffm forks and execute "mv" and the "-(" and "-[" files would be taken as options rather than filenames. This would be the similar to the problem you have with trying to use "rm" from the command line. Please confirm. I suppose a fix would be to allow only to rename files that start with "-". Other functions like "open with" would also do weird stuff with that kind of files so probably the be would be to disallow for everything except rename.
I'm pretty certain that things weren't sent to the wastebasket, just because the partition usage according to df is so much drastically smaller than it was (my home directory is on its own partition; actually, to be precicise, its own RAID1 over two drives), and a cursory search through xfce's files didn't turn anything up. If there's a particular place that I should look, though, please let me know and I'll confirm it. As to the fix idea, I'm not sure how one would implement that just because I've had issues with bash on this level as well. When I still used Gnome I got around it with that GUI, but I'm not sure how they addressed the problem.
I've tried to reproduce with files called -(test) and -[test] and both sending to wastebasket and unlinking work fine. This points to the problem being unrelated to file names. Rather it looks like it might be due to the following issue: When you expand a directory, say your homedir, the row which points to your homedir is selected. If you then scroll down and select a couple files with ctrl-click, your homedir will remain selected. Any option you then choose, like delete, will include your homedir since it is already selected. If you close confirm dialog quickly, chances are you will miss the issue. This behavior has caused some users to lose entire directories (although none has been homedir till now) and so it was changed for 4.2.3 (if xfce4-3 is ever released) and also in 4.3.x series.